Examine source code of Send URL to SMPlayer

{
  "manifest_version": 2,
  "name": "Send URL to SMPlayer",
  "version": "1.1",
  "description": "Send the current tab URL to SMPlayer",
  "icons": {
    "16": "assets/logo.svg",
    "32": "assets/logo.svg",
    "48": "assets/logo.svg",
    "64": "assets/logo.svg",
    "128": "assets/logo.svg",
    "256": "assets/logo.svg",
    "512": "assets/logo.svg"
  },
  "permissions": [
    "activeTab",
    "nativeMessaging",
    "storage",
    "notifications"
  ],
  "background": {
    "scripts": [
      "scripts/background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": "assets/logo.svg",
    "default_title": "Send URL to SMPlayer"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "af5bc4c0-4eec-4b1b-b30b-bd83d16436b9@SendUrlToSMPlayer"
    }
  },
  "options_ui": {
    "page": "html/options.html",
    "browser_style": true
  }
}